In the pressing of mats of material to produce pressed board and especially the formation of pressed board from sawdust, wood chips and wood fibers or other woody materials, a mat of such comminuted materials, generally mixed with a binder, is fed into the converging mouth of a continuous press between a pair of steel belts and is hot pressed therein to consolidate the material into a board.
A typical press of this type can include upper and lower press members mounted in a press stand with the upper and lower press members each including a respective endless steel press belt which cooperates with an endless circulating roller device, the roller bars of which brace the respective steel belts against heated press platens or plates. The lower member can include a lower horizontal beam on which the heated lower press platen is mounted while the upper member of the press has an upper beam on which its heated press platen is arranged. The rollers are supported by the press platens and, in turn, brace the steel belts. In the press of German Patent 31 33 792, at the mouth of the press a projecting tongue of a press platen can have its contour set so that when a bending moment is imparted to it, a preset contour can be established. This is used to adjust the contour of the converging mouth at the inlet side of the press. The fixing of the inlet contour has been found to be significant since the contour defines the starting conditions of the pressing operation and, in large measure, influences the quality of the product which can be obtained.
In the system of German Patent 31 33 792, the means for fixing the inlet contour, i.e. the contour of the mouth, was a row of spaced apart abutments in one embodiment and a displaceable wedge in another. The row of stops or abutments could not be readily adjusted without substantial downtime of the press and, while the wedge allowed a certain measure of adjustability, the configuration could not be statically determined for all positions of the wedge nor could a variety of curvatures be established in a well defined manner as was desirable.